Structure borne sound sources are vibrational source connected in some way to the building structure. They may be divided into impact sound and sound from mechanical excitation. The sound that is heard when people walk over floors in buildings is called impact sound. It is one of the most important aspects for the total acoustical quality of a building and it is usually dealt with as a first priority.

The remaining sound comes from building mechanicals including water taps, air conditioning, heating systems, and pumps. In the field of building acoustics, the treatment of those sources has become very important. Engineers describe the source, the receiver, and the point of contact on the receiver structure with accuracy to meet acoustic standards.